The field of the invention is centrifugal processors used in manufacturing flat media products.
The production of semiconductor wafers, substrates and photomask plates used in the manufacture of semiconductor wafers, has typically used processing equipment in which various types of processing fluids are used to treat the wafers. One example of a semiconductor processor is a centrifugal rinser-dryer used to rinse acids, caustics, etchants and other processing fluids from wafers, photomask plates, and similar units. The rinser-dryers are also used to dry the rinsed units using a flow of heated gas, such as nitrogen, which is passed through the processing chamber after rinsing with the desired fluid. The wafers are spun during processing to provide more even distribution of the processing fluids across the wafer surfaces and to assist in removal of rinsing liquids in preparation for drying.
Other types of semiconductor processors include acid and caustic treatment machines that spray of otherwise apply acids and caustics to the wafers or other flat media. Stripping processors are used to remove photoresist from the wafers. Other specific processing of wafers may require other types of chemicals. Many of these processes are appropriately performed in centrifugal processing machines to provide for even distribution of fluids over the wafer and to aid in removal of liquids.
A primary problem in the manufacturing semiconductor wafers is particle contamination. Contaminant particles can affect the photographic processes used to transfer the chip layouts onto the wafers being processed into chips. Contaminants on the photomasks can cause deterioration of the image being transferred onto the wafer. The direct processing of the wafers or other flat media themselves is even more susceptible to contamination because of the numerous processing steps, and the risk at each stage that contaminating particles can become adhered to the surface of the wafer. Particle contamination typically causes a large number of the devices on a wafer to be defective. Thus it is very important to reduce contamination to increase yields.
The costs of building and operating a modern semiconductor device manufacturing or fabrication facility now can often approach or exceed one billion dollars. Consequently, the amount of defect-free devices produced per hour/day/week is critical. As a result, there is a constant need to speed up the manufacturing processes. The centrifugal rinser-dryers described above are often used to rinse and dry wafers between various manufacturing steps. The drying process performed by current centrifugal rinser-dryers takes about 6-7 minutes. While centrifugal rinser-dryers have performed well in the past, faster drying is still needed. Many centrifugal rinser-dryers also use a purified gas, such as nitrogen, for drying, which adds to the manufacturing cost of the semiconductor devices.
It is therefore an object of the invention to provide an improved centrifugal rinser-dryer providing much faster drying.
It is also an object of the invention to provide very fast, yet low cost, drying methods.